The Parametric Step Function PDF is a binned distribution whose parameters
are the heights of each bin. This PDF was first used in BaBar's B0->pi0pi0
paper BABAR Collaboration (B. Aubert et al.) Phys.Rev.Lett.91:241801,2003.
This PDF may be used to describe oddly shaped distributions. It differs
from a RooKeysPdf or a RooHistPdf in that a RooParametricStepFunction
has free parameters. In particular, any statistical uncertainty in
sample used to model this PDF may be understood with these free parameters;
this is not possible with non-parametric PDFs.
The RooParametricStepFunction has Nbins-1 free parameters. Note that
the limits of the dependent varaible must match the low and hi bin limits.
An example of usage is:
Int_t nbins(10);
TArrayD limits(nbins+1);
limits[0] = 0.0; //etc...
RooArgList* list = new RooArgList("list");
RooRealVar* binHeight0 = new RooRealVar("binHeight0","bin 0 Value",0.1,0.0,1.0);
list->add(binHeight0); // up to binHeight8, ie. 9 parameters
RooParametricStepFunction aPdf = ("aPdf","PSF",*x,
*list,limits,nbins);

» Last changed: Tue Jun 30 16:33:35 2015 » Last generated: 2015-06-30 16:33This page has been automatically generated. For comments or suggestions regarding the documentation or ROOT in general please send a mail to ROOT support.